Seasonally snow covered alpine areas play a larger role in the hydrologic cycle than their area
would indicate. Their ecosystems may be sensitive indicators of climatic and atmospheric change.
Assessing the hydrologic and bio- geochemical responses of these areas to changes in inputs of water,
chemicals and energy should be based on a detailed understanding of watershed processes. This dissertation
discusses the development and testing of a model capable of predicting watershed hydrologic
and hydrochemical responses to these changes. The model computes integrated water and chemical
balances for watersheds with unlimited numbers of terrestrial, stream, and lake subunits, each of which
may have a unique, variable snow -covered area. Model capabilities include 1) tracking of chemical
inputs from precipitation, dry deposition, snowmelt, mineral weathering, basefiow or flows from areas
external to the modeled watershed, and user -defined sources and sinks, 2) tracking water and chemical
movements in the canopy, snowpack, soil litter, multiple soil layers, streamflow, between terrestrial
subunits (surface and subsurface movement), and within lakes (2 layers), 3) chemical speciation,
including free and total soluble species, precipitates, exchange complexes, and acid -neutralizing capacity,
4) nitrogen reactions, 5) a snowmelt optimization procedure capable of exactly matching observed
watershed outflows, and 6) modeling riparian areas. Two years of data were available for fitting and
comparing observed and modeled output. To the extent possible, model parameters are set based on
physical or chemical measurements, leaving only a few fitted parameters. The effects of snowmelt rate,
rate of chemical elution from the snowpack, nitrogen reactions, mineral weathering, and flow routing
on modeled outputs are examined.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/617630 |
| Date | 12 1900 |
| Creators | Wolford, Ross A. |
| Contributors | Department of Hydrology & Water Resources, The University of Arizona |
| Publisher | Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Technical Report |
| Source | Provided by the Department of Hydrology and Water Resources. |
| Rights | Copyright © Arizona Board of Regents |
| Relation | Technical Reports on Hydrology and Water Resources, No. 92-040 |
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